how much more should we not allow trees to be felled simply for the convenience of the international economy? >> very often we have a bigger impact with the congregation by talking to them about do you want to save money on your energy bill? and very seldom does the congregati say oh no. they usually say yes, how do we do that? >> the number of houses of worship that belong to ipl combine their purchasing power to buy cheaper electricity from renewable energy, at rates which can amount to huge savings, especially for the larger churches. ipl also encourages utilizing renewable energy like the solar panels on the roof of the shalom synagogue. >> we have saved many thousands of dollars over the course of 11 years running this building, because of passive solar technology. because of sensitive lightings that we put in place. it absolutely keeps operating costs down. if you make an investment in something like a really efficient boiler, it makes a tremendous difference. >> we're asking our congregations to serve as examples to the community. and then the hope is that when the religious leader ca